Process for the isolation of high boilers from the cyclooligomerization of 1,3-butadiene

Abstract

A process for the isolation of high-boiling monomers from distillation residue formed in the cyclodimerization and/or cyclotrimerization of 1,3-butadiene after target products of cyclooctadiene, vinylcyclohexene and/or cyclododecatriene have been separated off, comprising extracting the distillation residue with a nonpolar or slightly polar solvent, separating off insoluble oligomers and polymers that have at least partly crystallized by mechanical separation, removing the extractant, and isolating the high-boiling monomers.

What is claimed is:  
     
       1. A process for the isolation of high-boiling monomers from distillation residue formed in the cyclodimerization and/or cyclotrimerization of 1,3-butadiene after target products of cyclooctadiene, vinylcyclohexene and/or cyclododecatriene have been separated off, comprising: 
       extracting the distillation residue with an extract which is a nonpolar solvent selected from the group consisting of an unbranched or branched aliphatic hydrocarbon, a cycloaliphatic hydrocarbon, an unbranched or branched olefin hydrocarbon, and an unbranched or branched cycloaliphatic hydrocarbon or a slightly polar solvent selected from the group consisting of a branched or unbranched aliphatic ketone, branched or unbranched cycloaliphatic ketone, a branched or unbranched aliphatic aldehyde, and a branched or unbranched cycloaliphatic aldehyde, thereby obtaining an extract and an extraction residue,  
       separating off by mechnical separation oligomers and polymers which are insoluble in said extractant and that hace at least partly crystallized,  
       isolating the high-boiling monomers from a residue of the extract, after distillative removal the extractant.  
     
     
       2. The process as claimed in  claim 1 , wherein the extractant has a boiling point in the range from 35° C. to 130° C. 
     
     
       3. The process as claimed in  claim 2 , wherein the extractant has a boiling point in the range from 50° C. to 105° C. 
     
     
       4. The process as claimed in  claim 1 , wherein the extractant is acetone. 
     
     
       5. The process as claimed in  claim 4 , wherein the extractant is 2-butanone. 
     
     
       6. The process as claimed in  claim 1 , wherein the mechanical separation comprises sedimentation. 
     
     
       7. The process as claimed in  claim 1 , wherein the mechanical separation comprises filtration. 
     
     
       8. The process as claimed in  claim 1 , wherein further target product of the cyclodimerization or cyclotrimerization is isolated from the extract. 
     
     
       9. The process as claimed in  claim 1 , wherein the high-boiling monomers isolated comprise C 16  compounds. 
     
     
       10. The process as claimed in  claim 4 , wherein the mechanical separation comprises sedimentation. 
     
     
       11. The process as claimed in  claim 4 , wherein the mechanical separation comprises filtration. 
     
     
       12. The process as claimed in  claim 4 , wherein further target product of the cyclodimerization or cyclotrimerization is isolated from the extract. 
     
     
       13. The process as claimed in  claim 4 , wherein the high-boiling monomers isolated comprise C 16  compounds. 
     
     
       14. The process as claimed in  claim 5 , wherein the mechanical separation comprises sedimentation. 
     
     
       15. The process as claimed in  claim 5 , wherein the mechanical separation comprises filtration. 
     
     
       16. The process as claimed in  claim 5 , wherein further target product of the cyclodimerization or cyclotrimerization is isolated from the extract. 
     
     
       17. The process as claimed in  claim 5 , wherein the high-boiling monomers isolated comprise C 16  compounds.